{"id":39514,"date":"2025-11-06T18:04:15","date_gmt":"2025-11-06T23:04:15","guid":{"rendered":"https:\/\/stateofthenation.info\/?p=39514"},"modified":"2025-11-06T18:05:11","modified_gmt":"2025-11-06T23:05:11","slug":"10-major-anomalies-with-3i-atlas-according-to-former-harvard-chair-of-astronomy-department","status":"publish","type":"post","link":"https:\/\/stateofthenation.info\/?p=39514","title":{"rendered":"

10 Major Anomalies with 3I\/Atlas according to Former Chair of Harvard’s Astronomy Department<\/b><\/h2>"},"content":{"rendered":"

No Clear Cometary Tail in Post-Perihelion Images of 3I\/ATLAS<\/h2>\n

Avi Loeb<\/p>\n

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Post-perihelion image of the interstellar object 3I\/ATLAS, taken on November 5, 2025 by the R. Naves Observatory, shows a fuzzy ball of light. The Sunward direction is towards the bottom left corner (with the arrow on the left pointing in the anti-Sun direction). No obvious cometary tail is seen. (Credit:\u00a0R. Naves Observatory, Spain<\/a>)<\/figcaption><\/figure>\n

On November 5, 2025, two new images of the interstellar object\u00a03I\/ATLAS<\/a>\u00a0were released. They show a compact source of light without a clear cometary tail. The coma is not very different in morphology than its appearance in the Hubble Space Telescope on July 21, 2025 (accessible\u00a0here<\/a>).<\/p>\n

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Press enter or click to view image in full size<\/span><\/p>\n

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Post-perihelion image of 3I\/ATLAS, reported on November 5, 2025 by the Virtual Telescope Project. (Credit:\u00a0The Virtual Telescope Project<\/a>)<\/figcaption><\/figure>\n

This is surprising in view of NASA\u2019s JPL report\u00a0<\/mark>here<\/a><\/mark>\u00a0of a non-gravitational acceleration \u2014\u00a0<\/mark>normalized<\/a><\/mark>\u00a0at a heliocentric value of 1 au:<\/mark><\/p>\n

1. A radial acceleration away from the Sun of 1.1×10^{-6} au per day squared.<\/p>\n

2. A transverse acceleration relative to the Sun\u2019s direction of 3.7×10^{-7} au per day squared.<\/p>\n

Based on momentum conservation (as discussed\u00a0here<\/a>), I derived\u00a0here<\/a>\u00a0that the mass fraction lost during the perihelion passage of 3I\/ATLAS is larger than 13%.\u00a0For a typical comet, this should have resulted in a massive coma with dust and gas that would have been pushed by the solar radiation pressure and the solar wind to the shape of a typical cometary tail pointing away from the Sun. No such tail is visible in the new images from November 5, 2025.<\/mark><\/p>\n

In comparison, I include below an image of the solar system\u2019s comet\u00a0Lemmon<\/a>, taken by one of the telescopes that observed 3I\/ATLAS two days ago.\u00a0Lemmon features a clear cometary tail pointing away from the Sun, as expected.<\/mark><\/p>\n

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Press enter or click to view image in full size<\/span><\/p>\n

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Image of the comet\u00a0Lemmon<\/a>\u00a0from the solar system, taken on November 3, 2025 by the R. Naves Observatory, shows a clear cometary tail away from the Sun. (Credit:\u00a0R. Naves Observatory, Spain<\/a>)<\/figcaption><\/figure>\n

The anomalies displayed so far by 3I\/ATLAS include:<\/p>\n

1. Its retrograde trajectory is aligned to within 5 degrees with the ecliptic plane of the planets around the Sun, with a likelihood of 0.2% (see\u00a0here<\/a>).<\/p>\n

2. During July and August 2025, it displayed a sunward jet (anti-tail) that is not an optical illusion from geometric perspective, unlike familiar comets (see\u00a0here<\/a>).<\/p>\n

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